Re: [PATCH v3 3/3] mtd: spinand: add SPI-NAND MTD resume handler

From: Patrice CHOTARD
Date: Fri May 28 2021 - 04:23:07 EST


Hi Miquel

On 5/27/21 6:23 PM, Miquel Raynal wrote:
> Hi Patrice,
>
> + Pratyush
>
> <patrice.chotard@xxxxxxxxxxx> wrote on Thu, 27 May 2021 18:12:52 +0200:
>
>> From: Patrice Chotard <patrice.chotard@xxxxxxxxxxx>
>>
>> After power up, all SPI NAND's blocks are locked. Only read operations
>> are allowed, write and erase operations are forbidden.
>> The SPI NAND framework unlocks all the blocks during its initialization.
>>
>> During a standby low power, the memory is powered down, losing its
>> configuration.
>> During the resume, the QSPI driver state is restored but the SPI NAND
>> framework does not reconfigured the memory.
>>
>> This patch adds SPI-NAND MTD PM handlers for resume ops.
>> SPI NAND resume op re-initializes SPI NAND flash to its probed state.
>>
>> Signed-off-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>
>> Signed-off-by: Patrice Chotard <patrice.chotard@xxxxxxxxxxx>
>> ---
>> Changes in v3:
>> - Add spinand_read_cfg() call to repopulate cache
>>
>> Changes in v2:
>> - Add helper spinand_block_unlock().
>> - Add spinand_ecc_enable() call.
>> - Remove some dev_err().
>> - Fix commit's title and message.
>>
>> drivers/mtd/nand/spi/core.c | 33 +++++++++++++++++++++++++++++++++
>> 1 file changed, 33 insertions(+)
>>
>> diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
>> index 1f699ad84f1b..e3fcbcf381c3 100644
>> --- a/drivers/mtd/nand/spi/core.c
>> +++ b/drivers/mtd/nand/spi/core.c
>> @@ -1099,6 +1099,38 @@ static int spinand_block_unlock(struct spinand_device *spinand)
>> return ret;
>> }
>>
>> +static void spinand_mtd_resume(struct mtd_info *mtd)
>> +{
>> + struct spinand_device *spinand = mtd_to_spinand(mtd);
>> + int ret;
>> +
>> + ret = spinand_reset_op(spinand);
>> + if (ret)
>> + return;
>> +
>> + ret = spinand_read_cfg(spinand);
>> + if (ret)
>> + return;
>> +
>> + ret = spinand_init_quad_enable(spinand);
>> + if (ret)
>> + return;
>> +
>> + ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0);
>> + if (ret)
>> + return;
>> +
>> + ret = spinand_manufacturer_init(spinand);
>> + if (ret)
>> + return;
>> +
>> + ret = spinand_block_unlock(spinand);
>> + if (ret)
>> + return;
>> +
>> + spinand_ecc_enable(spinand, false);
>> +}
>
> Sorry for not being clear, but I think what Pratyush meant was that
> you could create a helper doing all the common initializations between
> spinand_init() and spinand_resume() and call it from these places to
> avoid code duplication. His comment somehow outclassed mine as I only
> focused on the unlock part (which I think is clearer anyway, please keep
> it like that).
>

My bad too, i read too quickly Pratyush's asnwer.
I am preparing a v4.

Thanks
Patrice


>> +
>> static int spinand_init(struct spinand_device *spinand)
>> {
>> struct device *dev = &spinand->spimem->spi->dev;
>> @@ -1186,6 +1218,7 @@ static int spinand_init(struct spinand_device *spinand)
>> mtd->_block_isreserved = spinand_mtd_block_isreserved;
>> mtd->_erase = spinand_mtd_erase;
>> mtd->_max_bad_blocks = nanddev_mtd_max_bad_blocks;
>> + mtd->_resume = spinand_mtd_resume;
>>
>> if (nand->ecc.engine) {
>> ret = mtd_ooblayout_count_freebytes(mtd);
>
> Thanks,
> Miquèl
>